A motor such as a permanent magnet motor includes a stator and a permanent magnet rotor. The permanent magnet rotor includes a permanent magnet and a magnet yoke. The magnet yoke is generally formed by stacking a plurality of laminations. Usually, the laminations are substantially circular sheets formed by stamping silicon steel sheets. There are mainly two types of permanent magnet rotors. One is an embedded type, i.e. the permanent magnet is embedded in the magnet yoke. The other is a surface mounted type, i.e. the permanent magnet is mounted to a surface of the magnet yoke. For the permanent magnet rotor of the embedded type, a gap between the permanent magnet and the magnet yoke is existed. The permanent magnet is usually fixed to the magnet yoke via adhesive, which is injected to the gap. However, this way makes a manufacturing of the rotor complicated.